The invention relates to a method and a device for coordinating a plurality of driving system devices of a vehicle.
Such a driving system device is, for example, a device for regulating the distance between vehicles for regulating the distance in relation to a vehicle travelling ahead (known by the applicant under the term “Distronic”), a speed regulating device (cruise controller), a collision avoidance device that, for example detects oncoming vehicles during overtaking maneuvers, a tire pressure monitoring system, a curve warning device for issuing prompt warnings of curves when the longitudinal velocity of a vehicle is too high, which device may also bring about braking and/or steering interventions in a further expansion level in order to prevent a vehicle from travelling through a curve at an unacceptably high speed, or any other driving system device which can be made available to the driver as an aid.
Such driving system devices may, on the one hand, merely have a warning function in order to draw the driver's attention to a specific driving state, for example if the tire pressure is not in a permitted range. However, there is also the possibility that the driving system devices automatically influence the driving state, for example, by means of a steering or braking intervention, without a manual intervention of the driver. For example, in some vehicles, it is already possible to provide a device for regulating the distance between vehicles, which automatically brakes the vehicle when the distance from the vehicle travelling ahead is too short. If a plurality of driving system devices are then to be integrated in one vehicle, it is necessary to ensure that any access to the actuator devices of the vehicle—for example the brake device or steering device—which are triggered by various driving system devices, both ensure safe driving and make it possible to maintain the correct functions of the various driving system devices.
Taking this as a starting point, the present invention is based on the object of providing a method, and a device for carrying out the method, which permits a plurality of driving system devices to be integrated in one vehicle while ensuring a safe driving state.
This object is achieved by providing a method and device for coordinating a plurality of driving system devices of a vehicle, a control result signal being generated from output signals of the driving system devices which are brought about as a function of current driving state variables of the vehicle and are used as a predefined setpoint value for influencing the driving state by means of at least one actuator device of the vehicle and/or a parameter result signal for influencing the regulating and/or control parameters of a driving state regulator or controller. When the control result signal and/or the parameter result signal is determined, a plurality of output signals which are present are then prioritized and/or weighted if these output signals originate from different driving system devices. The driving system devices are divided into a plurality of groups with different group priorities. The output signals of the driving system devices of a group with higher group priority are more heavily weighted during the determination of the control result signal and/or of the parameter result signal than the output signals of the driving system devices of a group with lower group priority.
The driving system devices which are provided in the vehicle generate output signals as a function of respectively determined driving state variables. The output variables constitute request signals for influencing the driving state or the regulation or control of the driving state. They are fed to a coordination device. This generates a control result signal and/or a parameter result signal as a function of the output signals which are present simultaneously. The control result signal is used as a predefined setpoint value for influencing the current driving state or the current movement of the vehicle. The respective actuator devices of the vehicle are activated as a function of the control result signal in order to bring about the desired movement of the vehicle or the desired driving state. The control parameters or regulating parameters for controlling or regulating the driving state, for example threshold values or parameters which characterize the vehicle, can be changed as a function of the parameter result signal so that it is possible to control or regulate the driving state in a way which can be adapted to the current driving state. The simultaneous uncoordinated access of the driving system devices to the actuator devices or the blocking of an access request of a driving system device merely because of the presence of an earlier access request to the same parameters or the same actuator devices is ruled out in the method according to the invention and the device according to the invention.
The driving system devices can also be simultaneously coordinated in terms of the feedback sent to the driver in order to inform him about the driving state. This is the subject-matter of a patent application submitted by the applicant on the same day, with the title “Verfahren und Vorrichtung zur Rückmeldung des Fahrzustandes eines Fahrzeugs an den Fahrer (Method and device for providing the driver with feedback on the driving state of a vehicle)” (applicants internal file No. P033161/DE/1), the specification of which is incorporated by reference herein.
Advantageous refinements of the method and of the device according to the invention emerge from the respective dependent claims.
The control result signal expediently corresponds to the setpoint driving state of the vehicle. The control result signal describes the setpoint movement of the vehicle in three-dimensional space. The control result signal thus defines the entire desired spatial movement of the vehicle.
Alternatively, it is also possible for the control result signal to correspond to the setpoint change in the driving state for the vehicle, in which case the control result signal describes the setpoint change in the movement of the vehicle in three-dimensional space. Here, only the desired change in movement of the vehicle is predefined as the setpoint value. The change in movement is defined for all the directions of movement in three-dimensional space.
In order to actuate the respective actuator devices, the control result signal can be transmitted directly to these actuator devices in order to influence the movement of the vehicle. It is possible here to superimpose a separate regulating operation for the dynamics of vehicle movement, which can be carried out in a known fashion by a driving state regulator or controller (for example ESP regulator) which is customary nowadays.
In another embodiment, the control result signal is transmitted to a driving state regulator or controller, in particular a regulator for the dynamics of vehicle movement, which produces actuation signals for the actuator devices in order to influence the movement of the vehicle. Thus, just one indirect transmission of the control result signal to the actuator devices is provided. The driving state regulator or controller evaluates the control result signal to determine whether there is a sufficiently stable overall driving state when the actuator device is actuated in accordance with the control result signal, and only generates, as a function of the evaluation result, actuation signals for the actuator devices which ensure an overall stable driving behavior. The driving state regulator or controller is therefore used, even before the actuation of the actuator devices, to check whether an unstable driving state could occur as a result of the actuation provided according to the control result signal, the actuator devices being then actuated in a correspondingly corrective fashion by the actuation signals.
It is also advantageous if the parameter result signal is transmitted to a driving state regulator or controller, in particular a regulator for the dynamics of vehicle movement, in order to influence the control parameters or regulating parameters of the driving state regulator or controller. The parameter result signal does not directly influence the actuation of the actuator devices, and thus the movement of the vehicle, but instead serves to change the regulating behavior or control behavior of the driving state regulator or controller by varying the regulating parameters or control parameters such as, for example, the triggering threshold or other parameters which characterize the driving behavior of the vehicle. In this way, adaptive regulation or control can be implemented.
During the determination of the control result signal and/or of the parameter result signal, it is possible for a plurality of output signals which are present to be prioritized and/or weighted if these output signals originate from different driving system devices. This measure makes it possible to coordinate a plurality of access requirements, present simultaneously, of a plurality of driving system devices with these actuator devices or the same parameters. The control result signal and the parameter result signal take into account here the importance of the output signals which are present for driving safety, weighting or prioritization being carried out in accordance with the evaluation of the importance of the output signals with respect to the instantaneous driving state of the vehicle.
In order to make possible a safer driving state of the vehicle, it is possible, when determining the control result signal and/or the parameter result signal, to take into account additional sensor signals which contain information relating to the current driving state of the vehicle, and/or input signals which correspond to manual predefined values of the driver. The output signals can then be prioritized or weighted taking into account the additional information of the sensor signals or of the input signals. The information from the additional input signals and sensor signals is used as evaluation criteria for the weighting and/or prioritization of the output signals in the determination of the two result signals. The sensor signals can contain, for example, current data relating to the yaw angle speed and/or the acceleration of the vehicle and/or the velocity of the vehicle and/or the wheel speeds and/or the steering wheel torque and/or the steering wheel angle. Of course, the acceleration of the vehicle or the velocity of the vehicle can be a three-dimensional vector variable in order to be able to specify the velocity or the acceleration in all the directions of movement of the vehicle, for example by reference to a Cartesian coordinate system which is usually used in vehicles and is fixed to the vehicle.
In order to determine the weighting of the various output signals, the driving system devices can be divided into a plurality of groups with different group priorities, the output signals of the driving system devices of one group with a higher group priority being more heavily weighted during the determination of the control result signal and/or the parameter result signal than the output signals of the driving system devices of a group with lower group priority. Here it is, for example, possible to assign the driving system devices which request an automatic safety intervention to a group with a high group priority, and the driving system devices which serve only to warn the driver to a group with a low group priority.
The output signals of the driving system devices are expediently present in the form of control signals for requesting an application of signals to actuator devices, or parameter signals for requesting that the regulating parameters and/or control parameters of the driving state regulating or controlling system should be influenced. The control result signal is determined as a function of the control signals, and the parameter result signal is determined as a function of the parameter signals.
One possible way of determining the control result signal or the parameter result signal is to form the sum of the control signals or parameter signals of the driving system devices which are each weighted with a weighting factor, in particular the sum of the individual weighting factors being equal to one, and the weighting factors being able to assume values in the region from zero to one. If a pure priority evaluation of the output signals which are present is to take place, it is possible, when evaluating the two output signals, to make in each case one weighting factor equal to one and all the other weighting factors equal to zero.
The weighting factors of the output signals can be predefined as a function of a driving system priority which is assigned to the respective driving system device. Different driving system priorities can be allocated with respect to the driving system devices of the same group of driving system devices, or with respect to all the driving system devices which are present.
In one variant which is easy to implement in order to determine the control result signal or the parameter result signal, only the output signals of the driving system devices of a single group are taken into account. Here, in particular, the group priorities of the groups of driving system devices whose driving system devices have produced output signals at the calculation time can be compared. The output signals of the driving system devices from the group of driving system devices with the comparatively highest group priority are then used to determine the two result signals.
In one expedient embodiment of the device according to the invention, the coordination device is integrated in a central processor unit together with the driving system devices and/or the driving state regulator or controller. The entire device requires little space and is better protected against interference, for example against external electromagnetic fields, owing to the short electrical connections between the components.
Furthermore, it is advantageous if the coordination device is connected to a sensor arrangement and/or an operator control arrangement so that the sensor signals, which are generated by the sensor arrangement and contain information relating to the current driving state of the vehicle, and/or the input signals of the operator control arrangement, which correspond to manual settings of the driver, can be transmitted to the coordination device in order to be taken into account in the determination of the control result signal and/or of the parameter result signal. At the same time, the coordination device receives additional information and data of the sensor arrangement, relating to the current driving state of the vehicle, independently of the output signals of the driving system devices. In this way, it is possible to ensure that the stability of the driving state is further improved as more information is made available to the coordination device than to the individual driving system devices.
In order to avoid additional or redundant sensors, it is possible here for one or more of the sensors of the sensor arrangement also to be used as a sensor for one or more of the driving system devices.
The method and device according to the invention will be explained in more detail below with reference to the appended drawing.